Advanced Diagnostics

Advanced Diagnostics - DTC P1684: Throttle Valve Return Spring Performance Problem






General Description
The electronic throttle control system controls the throttle valve opening. The system includes the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the electronic throttle control system (ETCS) control relay, the accelerator pedal position (APP) sensor, and the powertrain control module (PCM). The throttle valve default position spring is attached to the throttle valve gear. It opens the throttle valve to improve starting performance in cold conditions, or to retain minimum running performance in case of electronic throttle control system failure. If the throttle valve does not return to the default position when the throttle actuator moves to the default position from the middle position, the PCM detects a throttle valve return spring and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The throttle valve opening angle is 17° or more, or 11° or less, for at least 2.5 seconds.

Driving Pattern
1. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on.
2. Turn the ignition switch to LOCK (0), and wait 10 seconds.
3. Turn the ignition switch to ON (II).

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.